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+/* Copyright 2015 Google Inc. All Rights Reserved.
+
+ Distributed under MIT license.
+ See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
+*/
+
+/* Brotli state for partial streaming decoding. */
+
+#ifndef BROTLI_DEC_STATE_H_
+#define BROTLI_DEC_STATE_H_
+
+#include "../common/constants.h"
+#include "../common/dictionary.h"
+#include "../common/platform.h"
+#include "../common/transform.h"
+#include <brotli/types.h>
+#include "./bit_reader.h"
+#include "./huffman.h"
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+/* Graphviz diagram that describes state transitions:
+
+digraph States {
+ graph [compound=true]
+ concentrate=true
+ node [shape="box"]
+
+ UNINITED -> {LARGE_WINDOW_BITS -> INITIALIZE}
+ subgraph cluster_metablock_workflow {
+ style="rounded"
+ label=< <B>METABLOCK CYCLE</B> >
+ METABLOCK_BEGIN -> METABLOCK_HEADER
+ METABLOCK_HEADER:sw -> METADATA
+ METABLOCK_HEADER:s -> UNCOMPRESSED
+ METABLOCK_HEADER:se -> METABLOCK_DONE:ne
+ METADATA:s -> METABLOCK_DONE:w
+ UNCOMPRESSED:s -> METABLOCK_DONE:n
+ METABLOCK_DONE:e -> METABLOCK_BEGIN:e [constraint="false"]
+ }
+ INITIALIZE -> METABLOCK_BEGIN
+ METABLOCK_DONE -> DONE
+
+ subgraph cluster_compressed_metablock {
+ style="rounded"
+ label=< <B>COMPRESSED METABLOCK</B> >
+
+ subgraph cluster_command {
+ style="rounded"
+ label=< <B>HOT LOOP</B> >
+
+ _METABLOCK_DONE_PORT_ [shape=point style=invis]
+
+ {
+ // Set different shape for nodes returning from "compressed metablock".
+ node [shape=invhouse]; CMD_INNER CMD_POST_DECODE_LITERALS;
+ CMD_POST_WRAP_COPY; CMD_INNER_WRITE; CMD_POST_WRITE_1;
+ }
+
+ CMD_BEGIN -> CMD_INNER -> CMD_POST_DECODE_LITERALS -> CMD_POST_WRAP_COPY
+
+ // IO ("write") nodes are not in the hot loop!
+ CMD_INNER_WRITE [style=dashed]
+ CMD_INNER -> CMD_INNER_WRITE
+ CMD_POST_WRITE_1 [style=dashed]
+ CMD_POST_DECODE_LITERALS -> CMD_POST_WRITE_1
+ CMD_POST_WRITE_2 [style=dashed]
+ CMD_POST_WRAP_COPY -> CMD_POST_WRITE_2
+
+ CMD_POST_WRITE_1 -> CMD_BEGIN:s [constraint="false"]
+ CMD_INNER_WRITE -> {CMD_INNER CMD_POST_DECODE_LITERALS}
+ [constraint="false"]
+ CMD_BEGIN:ne -> CMD_POST_DECODE_LITERALS [constraint="false"]
+ CMD_POST_WRAP_COPY -> CMD_BEGIN [constraint="false"]
+ CMD_POST_DECODE_LITERALS -> CMD_BEGIN:ne [constraint="false"]
+ CMD_POST_WRITE_2 -> CMD_POST_WRAP_COPY [constraint="false"]
+ {rank=same; CMD_BEGIN; CMD_INNER; CMD_POST_DECODE_LITERALS;
+ CMD_POST_WRAP_COPY}
+ {rank=same; CMD_INNER_WRITE; CMD_POST_WRITE_1; CMD_POST_WRITE_2}
+
+ {CMD_INNER CMD_POST_DECODE_LITERALS CMD_POST_WRAP_COPY} ->
+ _METABLOCK_DONE_PORT_ [style=invis]
+ {CMD_INNER_WRITE CMD_POST_WRITE_1} -> _METABLOCK_DONE_PORT_
+ [constraint="false" style=invis]
+ }
+
+ BEFORE_COMPRESSED_METABLOCK_HEADER:s -> HUFFMAN_CODE_0:n
+ HUFFMAN_CODE_0 -> HUFFMAN_CODE_1 -> HUFFMAN_CODE_2 -> HUFFMAN_CODE_3
+ HUFFMAN_CODE_0 -> METABLOCK_HEADER_2 -> CONTEXT_MODES -> CONTEXT_MAP_1
+ CONTEXT_MAP_1 -> CONTEXT_MAP_2 -> TREE_GROUP
+ TREE_GROUP -> BEFORE_COMPRESSED_METABLOCK_BODY:e
+ BEFORE_COMPRESSED_METABLOCK_BODY:s -> CMD_BEGIN:n
+
+ HUFFMAN_CODE_3:e -> HUFFMAN_CODE_0:ne [constraint="false"]
+ {rank=same; HUFFMAN_CODE_0; HUFFMAN_CODE_1; HUFFMAN_CODE_2; HUFFMAN_CODE_3}
+ {rank=same; METABLOCK_HEADER_2; CONTEXT_MODES; CONTEXT_MAP_1; CONTEXT_MAP_2;
+ TREE_GROUP}
+ }
+ METABLOCK_HEADER:e -> BEFORE_COMPRESSED_METABLOCK_HEADER:n
+
+ _METABLOCK_DONE_PORT_ -> METABLOCK_DONE:se
+ [constraint="false" ltail=cluster_command]
+
+ UNINITED [shape=Mdiamond];
+ DONE [shape=Msquare];
+}
+
+
+ */
+
+typedef enum {
+ BROTLI_STATE_UNINITED,
+ BROTLI_STATE_LARGE_WINDOW_BITS,
+ BROTLI_STATE_INITIALIZE,
+ BROTLI_STATE_METABLOCK_BEGIN,
+ BROTLI_STATE_METABLOCK_HEADER,
+ BROTLI_STATE_METABLOCK_HEADER_2,
+ BROTLI_STATE_CONTEXT_MODES,
+ BROTLI_STATE_COMMAND_BEGIN,
+ BROTLI_STATE_COMMAND_INNER,
+ BROTLI_STATE_COMMAND_POST_DECODE_LITERALS,
+ BROTLI_STATE_COMMAND_POST_WRAP_COPY,
+ BROTLI_STATE_UNCOMPRESSED,
+ BROTLI_STATE_METADATA,
+ BROTLI_STATE_COMMAND_INNER_WRITE,
+ BROTLI_STATE_METABLOCK_DONE,
+ BROTLI_STATE_COMMAND_POST_WRITE_1,
+ BROTLI_STATE_COMMAND_POST_WRITE_2,
+ BROTLI_STATE_BEFORE_COMPRESSED_METABLOCK_HEADER,
+ BROTLI_STATE_HUFFMAN_CODE_0,
+ BROTLI_STATE_HUFFMAN_CODE_1,
+ BROTLI_STATE_HUFFMAN_CODE_2,
+ BROTLI_STATE_HUFFMAN_CODE_3,
+ BROTLI_STATE_CONTEXT_MAP_1,
+ BROTLI_STATE_CONTEXT_MAP_2,
+ BROTLI_STATE_TREE_GROUP,
+ BROTLI_STATE_BEFORE_COMPRESSED_METABLOCK_BODY,
+ BROTLI_STATE_DONE
+} BrotliRunningState;
+
+typedef enum {
+ BROTLI_STATE_METABLOCK_HEADER_NONE,
+ BROTLI_STATE_METABLOCK_HEADER_EMPTY,
+ BROTLI_STATE_METABLOCK_HEADER_NIBBLES,
+ BROTLI_STATE_METABLOCK_HEADER_SIZE,
+ BROTLI_STATE_METABLOCK_HEADER_UNCOMPRESSED,
+ BROTLI_STATE_METABLOCK_HEADER_RESERVED,
+ BROTLI_STATE_METABLOCK_HEADER_BYTES,
+ BROTLI_STATE_METABLOCK_HEADER_METADATA
+} BrotliRunningMetablockHeaderState;
+
+typedef enum {
+ BROTLI_STATE_UNCOMPRESSED_NONE,
+ BROTLI_STATE_UNCOMPRESSED_WRITE
+} BrotliRunningUncompressedState;
+
+typedef enum {
+ BROTLI_STATE_TREE_GROUP_NONE,
+ BROTLI_STATE_TREE_GROUP_LOOP
+} BrotliRunningTreeGroupState;
+
+typedef enum {
+ BROTLI_STATE_CONTEXT_MAP_NONE,
+ BROTLI_STATE_CONTEXT_MAP_READ_PREFIX,
+ BROTLI_STATE_CONTEXT_MAP_HUFFMAN,
+ BROTLI_STATE_CONTEXT_MAP_DECODE,
+ BROTLI_STATE_CONTEXT_MAP_TRANSFORM
+} BrotliRunningContextMapState;
+
+typedef enum {
+ BROTLI_STATE_HUFFMAN_NONE,
+ BROTLI_STATE_HUFFMAN_SIMPLE_SIZE,
+ BROTLI_STATE_HUFFMAN_SIMPLE_READ,
+ BROTLI_STATE_HUFFMAN_SIMPLE_BUILD,
+ BROTLI_STATE_HUFFMAN_COMPLEX,
+ BROTLI_STATE_HUFFMAN_LENGTH_SYMBOLS
+} BrotliRunningHuffmanState;
+
+typedef enum {
+ BROTLI_STATE_DECODE_UINT8_NONE,
+ BROTLI_STATE_DECODE_UINT8_SHORT,
+ BROTLI_STATE_DECODE_UINT8_LONG
+} BrotliRunningDecodeUint8State;
+
+typedef enum {
+ BROTLI_STATE_READ_BLOCK_LENGTH_NONE,
+ BROTLI_STATE_READ_BLOCK_LENGTH_SUFFIX
+} BrotliRunningReadBlockLengthState;
+
+typedef struct BrotliMetablockHeaderArena {
+ BrotliRunningTreeGroupState substate_tree_group;
+ BrotliRunningContextMapState substate_context_map;
+ BrotliRunningHuffmanState substate_huffman;
+
+ uint32_t sub_loop_counter;
+
+ uint32_t repeat_code_len;
+ uint32_t prev_code_len;
+
+ /* For ReadHuffmanCode. */
+ uint32_t symbol;
+ uint32_t repeat;
+ uint32_t space;
+
+ /* Huffman table for "histograms". */
+ HuffmanCode table[32];
+ /* List of heads of symbol chains. */
+ uint16_t* symbol_lists;
+ /* Storage from symbol_lists. */
+ uint16_t symbols_lists_array[BROTLI_HUFFMAN_MAX_CODE_LENGTH + 1 +
+ BROTLI_NUM_COMMAND_SYMBOLS];
+ /* Tails of symbol chains. */
+ int next_symbol[32];
+ uint8_t code_length_code_lengths[BROTLI_CODE_LENGTH_CODES];
+ /* Population counts for the code lengths. */
+ uint16_t code_length_histo[16];
+
+ /* For HuffmanTreeGroupDecode. */
+ int htree_index;
+ HuffmanCode* next;
+
+ /* For DecodeContextMap. */
+ uint32_t context_index;
+ uint32_t max_run_length_prefix;
+ uint32_t code;
+ HuffmanCode context_map_table[BROTLI_HUFFMAN_MAX_SIZE_272];
+} BrotliMetablockHeaderArena;
+
+typedef struct BrotliMetablockBodyArena {
+ uint8_t dist_extra_bits[544];
+ uint32_t dist_offset[544];
+} BrotliMetablockBodyArena;
+
+struct BrotliDecoderStateStruct {
+ BrotliRunningState state;
+
+ /* This counter is reused for several disjoint loops. */
+ int loop_counter;
+
+ BrotliBitReader br;
+
+ brotli_alloc_func alloc_func;
+ brotli_free_func free_func;
+ void* memory_manager_opaque;
+
+ /* Temporary storage for remaining input. Brotli stream format is designed in
+ a way, that 64 bits are enough to make progress in decoding. */
+ union {
+ uint64_t u64;
+ uint8_t u8[8];
+ } buffer;
+ uint32_t buffer_length;
+
+ int pos;
+ int max_backward_distance;
+ int max_distance;
+ int ringbuffer_size;
+ int ringbuffer_mask;
+ int dist_rb_idx;
+ int dist_rb[4];
+ int error_code;
+ uint8_t* ringbuffer;
+ uint8_t* ringbuffer_end;
+ HuffmanCode* htree_command;
+ const uint8_t* context_lookup;
+ uint8_t* context_map_slice;
+ uint8_t* dist_context_map_slice;
+
+ /* This ring buffer holds a few past copy distances that will be used by
+ some special distance codes. */
+ HuffmanTreeGroup literal_hgroup;
+ HuffmanTreeGroup insert_copy_hgroup;
+ HuffmanTreeGroup distance_hgroup;
+ HuffmanCode* block_type_trees;
+ HuffmanCode* block_len_trees;
+ /* This is true if the literal context map histogram type always matches the
+ block type. It is then not needed to keep the context (faster decoding). */
+ int trivial_literal_context;
+ /* Distance context is actual after command is decoded and before distance is
+ computed. After distance computation it is used as a temporary variable. */
+ int distance_context;
+ int meta_block_remaining_len;
+ uint32_t block_length_index;
+ uint32_t block_length[3];
+ uint32_t num_block_types[3];
+ uint32_t block_type_rb[6];
+ uint32_t distance_postfix_bits;
+ uint32_t num_direct_distance_codes;
+ uint32_t num_dist_htrees;
+ uint8_t* dist_context_map;
+ HuffmanCode* literal_htree;
+ uint8_t dist_htree_index;
+
+ int copy_length;
+ int distance_code;
+
+ /* For partial write operations. */
+ size_t rb_roundtrips; /* how many times we went around the ring-buffer */
+ size_t partial_pos_out; /* how much output to the user in total */
+
+ /* For InverseMoveToFrontTransform. */
+ uint32_t mtf_upper_bound;
+ uint32_t mtf[64 + 1];
+
+ /* Less used attributes are at the end of this struct. */
+
+ /* States inside function calls. */
+ BrotliRunningMetablockHeaderState substate_metablock_header;
+ BrotliRunningUncompressedState substate_uncompressed;
+ BrotliRunningDecodeUint8State substate_decode_uint8;
+ BrotliRunningReadBlockLengthState substate_read_block_length;
+
+ unsigned int is_last_metablock : 1;
+ unsigned int is_uncompressed : 1;
+ unsigned int is_metadata : 1;
+ unsigned int should_wrap_ringbuffer : 1;
+ unsigned int canny_ringbuffer_allocation : 1;
+ unsigned int large_window : 1;
+ unsigned int size_nibbles : 8;
+ uint32_t window_bits;
+
+ int new_ringbuffer_size;
+
+ uint32_t num_literal_htrees;
+ uint8_t* context_map;
+ uint8_t* context_modes;
+
+ const BrotliDictionary* dictionary;
+ const BrotliTransforms* transforms;
+
+ uint32_t trivial_literal_contexts[8]; /* 256 bits */
+
+ union {
+ BrotliMetablockHeaderArena header;
+ BrotliMetablockBodyArena body;
+ } arena;
+};
+
+typedef struct BrotliDecoderStateStruct BrotliDecoderStateInternal;
+#define BrotliDecoderState BrotliDecoderStateInternal
+
+BROTLI_INTERNAL BROTLI_BOOL BrotliDecoderStateInit(BrotliDecoderState* s,
+ brotli_alloc_func alloc_func, brotli_free_func free_func, void* opaque);
+BROTLI_INTERNAL void BrotliDecoderStateCleanup(BrotliDecoderState* s);
+BROTLI_INTERNAL void BrotliDecoderStateMetablockBegin(BrotliDecoderState* s);
+BROTLI_INTERNAL void BrotliDecoderStateCleanupAfterMetablock(
+ BrotliDecoderState* s);
+BROTLI_INTERNAL BROTLI_BOOL BrotliDecoderHuffmanTreeGroupInit(
+ BrotliDecoderState* s, HuffmanTreeGroup* group, uint32_t alphabet_size_max,
+ uint32_t alphabet_size_limit, uint32_t ntrees);
+
+#define BROTLI_DECODER_ALLOC(S, L) S->alloc_func(S->memory_manager_opaque, L)
+
+#define BROTLI_DECODER_FREE(S, X) { \
+ S->free_func(S->memory_manager_opaque, X); \
+ X = NULL; \
+}
+
+#if defined(__cplusplus) || defined(c_plusplus)
+} /* extern "C" */
+#endif
+
+#endif /* BROTLI_DEC_STATE_H_ */